Electrical contact.



H. ANscHUTZ-KAEMPFE. ELECTRICAL CONTACT. APPLICATION FILED SEPT. 7. 19H.

Patented Feb. 1, 1916.

in section, for supplying v y circular member to a part concentrically roby means UNITED STATES HERMANN ANSCHTLKAEMPEE, or NEUMHLEN, NEAE KIEL, GERMANY." A

ELECTRICAL CONTACT.

Application filed September 7, 1911. Serial No. 648,248.

To all whom t may concern.'

Be it known that I, Dr. HERMANN AN- sCHTz-KAEMPFE, a subject of the Emperor of Germany, residing at Heikendorferweg 9, Neumhlen, ventedcertain newand useful Improvements in or Relating to Electrical Contacts, of which the following is a specification.

Mercury contacts which are used in electrical apparatus for supplying current to moving parts, when the method of operating the apparatus in question precludes any danger of the mercury escaping.

The object of this invention is to avoidk this limitation of theapplication of mer-` cury or like contacts.

The invention consistsl in giving the two parts of the apparatus to be electrically connected together by the Contact such ashape and arranging them relatively to each other in such a way that the escape of the mercury is rendered impossible by reason of its own cohesion. u

Several constructions and methods of applications of the invention are illustrated by way of example 'in the accompanying drawing in whic Figure 1 shows an arrangement for the supply of current to a rotating spindle. Figs. 2 and 3 show a different construction for the supply of current to a rotating crank, and Figs.'4 and 5 are respectively a plan and side elevation of apparatus partly current from a tating with regard to the member.

In all these constructions of the contact, the part which contains the mercury, that is to say, the part with can beV brought into any desired position without any fear'of spilling the mercury.

-In Fig.1, 1 is apart of an electrical apparatus from which the current admitted through the wires 2, is to be supplied to a rotating spindle 3. To that end, the part 1 is provided with a recess 4v containing mercury, into which the spindle 3 penetrates of a pin 5. In order tof prevent the mercury from escaping when the part 1 is not standing still, but is moved in anydesired manner, it is provided with a cover 6 which surrounds the pin 5 so closely that only a very narrow slot is left which may be compared to a capillary vessel. In this case, the mercury lcannot escape from the i Specification of Letters Patent.

near Kiel, Germany, have in- 'l are generally satisfactory only.

the mercury cup,

.- Figs. 4 and 5 show the construction of a vby means of a point PATENT OFFICE.

v retenteareb. 1,1916.

cup 4, even when the parts are moved in any desired manner,'or placed upside down, as the-cohesion of the mercury prevents it from escaping. The dimensions of the-part 1, the pin 5 and the mercury cup 4, are callculated'so thatcurrent of a very considerable strength can be transmitted. The spindle 3 may be supported by parts (not shown) so as not to rest upon the cover 6.

Fig. 2 shows the application of the invention to an electric connection between a rotatable crank and the crank bearing, which can be used for numerous feed-apparatus, regulating resistances, etc. The part 1 is provided with a mercury cup-4 into which is introduced a crank pin 7 held fast, for instance by a screw 8,- plate 9 and washer 10. The crank pin must lit fairly closely in its bearing', so that the space between the two constitutes in e'ect a capillary vessel, and the mercury contained therein is retained in the cup by cohesion, even when the parts are turned to an angle of 90, or even 180 from the position shown in Fig. 2. The mercury acts at the same time as a lubricating medium. The width of the intermediate space left between the crank pin 7 and the walls of the mercury cup 4, is shown in the'drawing on an enlarged scale, merely for the sake of clearness.

In Fig. 3 the crank pin 7 is assumed to be inserted into its bearing in part 1 in a fairly tight manner, and is provided laterally with -a recess 11 in which is introduced mercury. This mercury which is carried around during the rotation of the crank pin, forms an always reliable electric connection betweenthe crank pin and the part 1, but it cannot escape, whatever be the changes of position of vthe art l, as the space'left between the parts land 1 is too narrow. Obviously y the materials from which the parts 1, 5, 7, etc., are made, must be of the kindwhi'ch are not corroded by mercury.

good electric connection -offering only a slight frictional resistance, between a circular member 12 and a body 13 which can be rotated about its spindle 14 in the direction of the two arrows 15. This is an arrangement such as for instance frequently' used for transmission of readings of indices to a distance. In this case, the mercury cup 4 is rranged in a ball 16; into a mercury cup' dips a pin 17 which forms, o n the one hand, 18, and on the other hand by means of the neck 19, two bearings for the ball, about which the latter canrotate. 'Ihe ball is prevented from shifting in the direction of the axis of the pin 17 by a collar which engages under the cover 21 of the mercury cup surrounding the neck 19 and is secured to the ball in any desired manner. rIhe pin 17 or its neck 19, is connected to the part 13 by means of a flexible shaft 22, and the relative position of the parts 12 and 13 is calculated so that the axis of the pin 17 is approximately parallel to the axis of rotation 14 of the part 13, when the circumference of the ball 16 is resting on the bar 12.

The mercury in the cup 4f forms, as will be seen, a reliable electric connection ,between the ball 16 and the pin 17, the shaft 22 electrically connected to the latter, and

the further conductors on the part 13. 'Ihe mercury cannot escape from the cup 4, as the space left between the neck 19 and the cover 21 of the mercury cup, is so narrow that it constitutes a capillary vessel. If the part 13 rotates relatively to the bar 12, the ball 16 will roll. on the said bar, so that the friction is therefore a rolling, and not a sliding one, and thus the frictional resistance is correspondingly decreased. For improving the electric connection the bar 12 as well as the contact zone of the ball, can be provided with a silver or platinum lining 23.

In theconstruction shown in the drawing, it is assumed that electric connection between 12 and 13 takes place only during the rotation ofy13 from a given position of rest in one orthe other direction. For that reason, the bar 12 is made of two parts separated by a space or gap 24 and connected together by an insulating part 25. This arrangement has however nothing to do with the invention;

Obviously instead of mercury, any other electrolyze.

conducting liquids can be used which do not 2. Ina mercury electrical contact, the

combination of a spherical cup to hold the mercury and a pin, entering said cup and surrounded by but spaced from the inner wall thereof, on which the cup is carried rotatably, the space between cup and pin being of capillary dimensions where the pin enters said cup.

3. An electrical contact comprising a fixed contact pin, a bearing for said pin adapted to rotate thereupon and having inner surfaces separated from the pin so as to form a space for mercury said space being so small .where the pin enters the bearing that the mercury will be maintained by cohesion, and a member upon which said bearing is adapted to roll; v

4. An electrical contact comprising a pivoted arm carrying a ixed pin, a spherical cup rotatably mountedupon said pin said cup being adapted to contain mercury and the pin projecting into the cup but spaced from the inner wall thereof, the pin as it enters the cup being separated therefrom by a capillary space, and a track upon which said cup is adapted toroll as the arm moves upon itsy pivot.'

In witness whereof I have hereunto signed my name this 19th day of August 1911 in the presence of two subscribing witnesses.

DR. HERMANN ANSCHTZ-KAEMPFE.

Witnesses:

HUGO LIEBoL'r, KURT BUNDE. 

